Not Applicable
Not Applicable
This invention relates generally to a weight measurement system for measuring the receiving weight of a payload. The weight measurement system is used in conjunction with a conveyor system and constructed such as to enable containers to be removed from a truck via a forklift and placed upon the conveyor-based scale system such that time and operating steps are saved in the weighing cycle in order to facilitate a faster unloading operation. The invention also has particular utility in a weight measurement system for livestock including poultry wherein the payload is processed quickly upon receipt at the processing center, and an accurate and fast measurement system is desirable.
In many production facilities, the weight of a raw material or production input is a critical factor that must be closely monitored. For example, in a production process characterized by one primary raw product input used in high volumes, the weight of the raw material is perhaps the most closely monitored production variable. In addition to production control, the price or value of the raw material is often a function of weight. Accordingly, accurate payment for said raw material requires accuracy in weight measurement.
In situations in which a raw material is transported to a production facility by trucks, quite often the delivery trucks are unloaded by means of a forklift or other hydraulic lift devices. In the typical scenario, a pallet or skid, usually constructed of wood or heavy polymer material, is used to support the container(s) of material from the interior bed of the truck. Pallets are arranged such that the tines of a forklift will easily engage the pallet for lifting, removal and placement at the production center. Quite often, the first function performed when a pallet of material is removed from a truck is the weighing of such pallets in order to verify or otherwise identify proper weight, and hence, payment. Accordingly, each pallet of material is placed onto a scale system of some sort. The weighing of individual pallets, however, can often be time consuming resulting in increased transportation costs for a given load. Accordingly, any weight measurement system that facilitates a fast and easy weighing of a load is highly advantageous.
In addition to speed and cost considerations, in scenarios in which the raw product in question is livestock or live animals such as poultry, a fast and effective weight measurement system is even more important. Poultry is typically shipped in large steel cage containers constructed to accommodate loading and unloading by forklift. In a poultry production facility, it is important to weigh a received load of chickens as soon as possible after the load is removed from the delivery truck. In the event that a delay occurs, the chickens may dry out or otherwise be affected by environmental conditions such as to diminish desirability of the chickens. In addition, delays in processing time for the chickens also results in an increased potential for disease transmission and death losses to the load before they can be processed. Accordingly, it is even more desirable to weigh the load immediately after it is removed from the delivery truck.
A wide assortment of prior art attempts have been made to address the problem of providing a fast and effective means of accelerating the weighing function for a raw material load. Such prior art devices include static batch weight systems as well as dynamic systems and even forklift-mounted scale systems. Many of these devices are directed specifically to address the problems described above, but unfortunately, many of these devices introduce additional complications or drawbacks of their own.
U.S. Pat. No. 4,533,008 to Ostermann discloses a livestock scale system that generally resembles a combination of a utility wagon and a standard weight-slide mechanical scale system. The weight measurement system includes primary and secondary scale arms that are pivotally connected to a weight support apparatus. The system is mobile and can optimally be used to measure, for example, a litter of pigs or other livestock.
U.S. Pat. No. 5,666,295 to Bruns discloses a dynamic weight measurement system for operation with a hydraulic lift mechanism such as a forklift. Bruns notes and describes various other hydraulic lift weighing devices and boasts that his invention is less susceptible to accuracy degradation as a result of mechanical disturbances such as vibration or shifting of the load. Bruns operates by taking a plurality of pressure measurement readings during the time the load is supported by the hydraulic lift. The measurements are stored in a memory device and a microprocessor fine tunes the weight measurement while filtering unwanted signals associated with vibration or other mechanical disturbances. The Bruns mechanism essentially reads weight only during the portion of the lift in which acceleration of the forklift tines has ceased such that the pressure measurements are not affected by that factor. The device is otherwise a conventional fork truck with a cylinder housing a piston attached to the mast. A pressure transducer regulates hydraulic pressure and creates electrical signals corresponding to the weight resistance. The electrical signals are transmitted to processing circuitry which includes a microprocessor and a first and second memory element. While novel in many respects, the Bruns method is more complicated than would otherwise be necessary, as a result of the inherent difficulty associated with a scale system which is mobile with respect to the Earth.
Another forklift-based weight measurement system is disclosed in U.S. Pat. No. 5,986,560 by Rayburn. The Rayburn device includes one or more weight sensing means embedded in the tines of a forklift such as to measure the weight of an object resting upon the forklift. The weight system means is in communication with a display means preferably mounted on the dashboard, to be read by the operator. The invention further discloses a novel wiring assembly for use with such modified forklift blades. In addition to providing weight measurement, the Rayburn system enables an operator to know immediately whether or not the weight limitations of the forklift are being exceeded. However, the Rayburn device does not provide automatic feedback of the measured quantities to a production system wherein such information may be needed.
U.S. Pat. No. 4,491,190 to Mayfield discloses a weight measurement apparatus designed to be affixed to vehicles for lifting, transporting, loading, and simultaneously weighing an object. Specifically, the Mayfield device is designed to be attached to a farm implement such as a tractor in order to weigh and transport material, and is especially directed to weighing and transporting round hay bales. The device is similar in appearance to a pair of forklift tines and the frame members are closely linked by a parallelogram linkage system in a manner allowing some relative parallel-planar longitudinal movement while restricting relative lateral movement.
U.S. Pat. No. 4,638,876 by Balduin et al. is a weight measurement system designed to be effective on eccentric loads or objects which are irregular in weight distribution. The device consists essentially of a weighing plate mounted upon three essentially triangularly arranged weight cells which communicate with a computing device for weight measurement. The Balduin device may be mounted on a forklift while still allowing flexibility in the arrangement of the load with respect to the weight cells and the forklift tines. However, the Balduin device has little application to a conveyor arrangement and would not perform optimally in situations where the load is moving.